docs: def heightmap_lerp_hm(
      hm1: np.ndarray, hm2: np.ndarray, hm3: np.ndarray, coef: float
  ) -> None:
      """Perform linear interpolation between two heightmaps storing the result
      in ``hm3``.
  
      This is the same as doing ``hm3[:] = hm1[:] + (hm2[:] - hm1[:]) * coef``
  
      Args:
          hm1 (numpy.ndarray): The first heightmap.
          hm2 (numpy.ndarray): The second heightmap to add to the first.
          hm3 (numpy.ndarray): A destination heightmap to store the result.
          coef (float): The linear interpolation coefficient.
      """
      lib.TCOD_heightmap_lerp_hm(
          _heightmap_cdata(hm1),
          _heightmap_cdata(hm2),
          _heightmap_cdata(hm3),
          coef,
      )